From: Jan Kara Subject: Re: [PATCH v2 3/4] ext4: remove unnecessary superblock dirtying Date: Mon, 2 Apr 2012 23:49:51 +0200 Message-ID: <20120402214951.GA5270@quack.suse.cz> References: <1333367140-28370-1-git-send-email-artem.bityutskiy@linux.intel.com> <1333367140-28370-5-git-send-email-artem.bityutskiy@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ted Tso , Linux Kernel Maling List , Linux FS Maling List , Ext4 Mailing List , Jan Kara To: Artem Bityutskiy Return-path: Content-Disposition: inline In-Reply-To: <1333367140-28370-5-git-send-email-artem.bityutskiy@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon 02-04-12 14:45:39, Artem Bityutskiy wrote: > From: Artem Bityutskiy > > This patch changes the '__ext4_handle_dirty_super()' function which is used > by ext4 to update the super-block via the journal in the following cases: > > 1. When creating the first large file on a file > system without EXT4_FEATURE_RO_COMPAT_LARGE_FILE feature. > 2. When re-sizing the file-system > 3. When creating an xattr on a file-system without the > EXT4_FEATURE_COMPAT_EXT_ATTR feature. > > This function, however, falls back to just marking the superblock as dirty > if the file-system has no journal. But it is user really rarely and it does not > give any benefit to use the delayed superblock write (via the VFS's > 'sync_supers()' kernel thread) in these cases. We can just write out the > superblock asynchronously instead. > > This patch also removes 's_dirt' condition on the unmount path because we never > set it anymore, so we should not test it. > > Tested using xfstests for both journalled and non-journalled ext4. > > Signed-off-by: Artem Bityutskiy Looks good. Reviewed-by: Jan Kara Honza > --- > fs/ext4/ext4.h | 1 + > fs/ext4/ext4_jbd2.c | 2 +- > fs/ext4/super.c | 5 ++--- > 3 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index aba3749..ba2cf3f 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1953,6 +1953,7 @@ extern int ext4_group_extend(struct super_block *sb, > extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count); > > /* super.c */ > +int ext4_commit_super(struct super_block *sb, int sync); > extern void *ext4_kvmalloc(size_t size, gfp_t flags); > extern void *ext4_kvzalloc(size_t size, gfp_t flags); > extern void ext4_kvfree(void *ptr); > diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c > index aca1790..a85f46f 100644 > --- a/fs/ext4/ext4_jbd2.c > +++ b/fs/ext4/ext4_jbd2.c > @@ -149,6 +149,6 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line, > ext4_journal_abort_handle(where, line, __func__, > bh, handle, err); > } else > - sb->s_dirt = 1; > + err = ext4_commit_super(sb, 0); > return err; > } > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index ceebaf8..6b45785 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -63,7 +63,6 @@ static struct ext4_features *ext4_feat; > static int ext4_load_journal(struct super_block *, struct ext4_super_block *, > unsigned long journal_devnum); > static int ext4_show_options(struct seq_file *seq, struct dentry *root); > -static int ext4_commit_super(struct super_block *sb, int sync); > static void ext4_mark_recovery_complete(struct super_block *sb, > struct ext4_super_block *es); > static void ext4_clear_journal_err(struct super_block *sb, > @@ -853,7 +852,7 @@ static void ext4_put_super(struct super_block *sb) > EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER); > es->s_state = cpu_to_le16(sbi->s_mount_state); > } > - if (sb->s_dirt || !(sb->s_flags & MS_RDONLY)) > + if (!(sb->s_flags & MS_RDONLY)) > ext4_commit_super(sb, 1); > > if (sbi->s_proc) { > @@ -3991,7 +3990,7 @@ static int ext4_load_journal(struct super_block *sb, > return 0; > } > > -static int ext4_commit_super(struct super_block *sb, int sync) > +int ext4_commit_super(struct super_block *sb, int sync) > { > struct ext4_super_block *es = EXT4_SB(sb)->s_es; > struct buffer_head *sbh = EXT4_SB(sb)->s_sbh; > -- > 1.7.7.6 > -- Jan Kara SUSE Labs, CR